Buggy code:
public class JRubyPlugin extends JavaPlugin { private static final Class < Listener > eventHandlerClass ; private static final ImmutableSet < RukkitEvent > allEvents ; private static boolean ableToAutoHandle ( RukkitEvent event ) { } private static Iterable < RukkitEvent > listEvents ( ) { } private static Listener newDynamicEventHandler ( JRubyPlugin that ) { } private final AtomicReference < RubyEnvironment > jruby = new AtomicReference < > ( ) ; private final AtomicReference < FileConfiguration > config = new AtomicReference < > ( ) ; private Jedis jedis ; public Jedis getJedis ( ) { } public void reloadPlugins ( ) { } public void updatePlugins ( ) { } private void reloadPlugins ( final boolean refreshDependencies ) { } Object fireEvent ( String method , Object ... args ) { } private Object fireEvent ( RubyEnvironment env , String method , Object ... args ) { } private void firePluginEnableEvent ( ) { } private void firePluginEnableEvent ( RubyEnvironment env ) { } private void firePluginDisableEvent ( ) { } private void firePluginDisableEvent ( RubyEnvironment env ) { } private void applyEventHandler ( ) { } @ Override public void onEnable ( ) { Configuration config = getConfig ( ) ; { final String host = config . getString ( "rukkit.redis.host" , "localhost" ) ; final int port = config . getInt ( "rukkit.redis.port" , DEFAULT_PORT ) ; getLogger ( ) . info ( "--><seq2seq4repair_space>Connecting<seq2seq4repair_space>redis..." ) ; try { jedis = new Jedis ( host , port ) ; jedis . connect ( ) ; getLogger ( ) . info ( "----><seq2seq4repair_space>Use<seq2seq4repair_space>it<seq2seq4repair_space>for<seq2seq4repair_space>core<seq2seq4repair_space>storage." ) ; String resp = jedis . select ( 0 ) ; <START_BUG> if ( ! ( "" . equals ( resp ) ) ) { <END_BUG> for ( String line : resp . split ( "\r?\n" ) ) { getLogger ( ) . info ( ( "------><seq2seq4repair_space>" + line ) ) ; } } getLogger ( ) . info ( "----><seq2seq4repair_space>Connected." ) ; } catch ( Exception e ) { jedis = null ; getLogger ( ) . warning ( ( ( ( "----><seq2seq4repair_space>Failed<seq2seq4repair_space>to<seq2seq4repair_space>connect<seq2seq4repair_space>" + host ) + ":" ) + port ) ) ; getLogger ( ) . warning ( Throwables . getStackTraceAsString ( e ) ) ; } } updatePlugins ( ) ; getLogger ( ) . info ( "--><seq2seq4repair_space>Save<seq2seq4repair_space>all<seq2seq4repair_space>event<seq2seq4repair_space>names<seq2seq4repair_space>to<seq2seq4repair_space>file." ) ; try { if ( config . contains ( "rukkit.event_filename" ) ) { writeEvents ( new File ( config . getString ( "rukkit.event_filename" ) ) . toPath ( ) , JRubyPlugin . allEvents ) ; getLogger ( ) . info ( "--><seq2seq4repair_space>Saved." ) ; } else { getLogger ( ) . info ( "--><seq2seq4repair_space>No<seq2seq4repair_space>filename,<seq2seq4repair_space>skipped." ) ; } } catch ( Exception e ) { getLogger ( ) . warning ( "--><seq2seq4repair_space>Failed<seq2seq4repair_space>to<seq2seq4repair_space>save<seq2seq4repair_space>event<seq2seq4repair_space>names<seq2seq4repair_space>to<seq2seq4repair_space>file:" ) ; getLogger ( ) . warning ( Throwables . getStackTraceAsString ( e ) ) ; } getLogger ( ) . info ( "Rukkit<seq2seq4repair_space>enabled!" ) ; applyEventHandler ( ) ; } @ Override public void onDisable ( ) { } @ Override public boolean onCommand ( CommandSender sender , Command command , String label , String [ ] args ) { } @ Override public List < String > onTabComplete ( CommandSender sender , Command command , String alias , String [ ] args ) { } @ Override public FileConfiguration getConfig ( ) { } private void writeEvents ( Path path , Iterable < ? extends RukkitEvent > events ) throws IOException { } }

Fix:
if ( ( resp != null ) && ( ! ( "" . equals ( resp ) ) ) ) {